2007UL 991 CRD-2007 UL Standard for Safety Tests for Safety-Related Controls Employing Solid-State Devices - Section/Paragraph Reference: Section 18 (Edition 3: October 22, 2004)
2004UL 991-2004 UL Standard for Safety Tests for Safety-Related Controls Employing Solid-State Devices Third Edition; Reprint with revisions through and including April 2, 2008
2000UL 991 BULLETIN-2000 UL Standard for Safety Tests for Safety-Related Controls Employing Solid-State Devices
1995UL 991-1995 Tests for safety-related controls employing solid-state devices
1989UL 991-1989 Tests for safety-related controls employing solid-state devices